Bekhorot 18 – בכורות י״ח | Daf Yomi with Rashi, Tosafot, the Rambam and halacha

What Bekhorot 18 teaches

Human measurements cannot be exact, so bordering towns bring one broken-necked heifer in partnership with a mutual stipulation.
Rabbi Akiva awards the priest only the leaner twin, forcing the priest to prove he deserves the fatter one.
Rabbi Yosei exempts the retained doubtful twin from foreleg, jaw, and maw gifts because constructive acquisition replaces it.

The sugyot

The Gemara investigates whether humans can achieve exact measurement and concludes from the broken-necked heifer that the Rabbis hold absolute precision is impossible.
The Gemara explains that Rabbi Tarfon awards the priest the superior twin, whereas Rabbi Akiva grants the priest only the leaner twin.
The Gemara examines why Rabbi Meir obligates priestly gifts from a doubtfully-born second lamb, while Rabbi Yosei exempts it through constructive acquisition.
All agree a doubtful firstborn without replacements requires priestly gifts, while a doubtful animal tithe is completely exempt from priestly gifts.
The Gemara resolves a contradiction in Rabbi Tarfon's ruling by establishing that he retracted his view that the priest takes the better lamb.
The Gemara harmonizes Rabbi Tarfon and Rabbi Akiva through two deposit parables, locating their debate in whether an owner grants a priest courtyard rights.
The Mishnah details doubtful firstborn cases among mixed births, establishing which animals go to the priest and whether remaining animals owe priestly gifts.
The Gemara demonstrates why the dispute between Rabbi Tarfon and Rabbi Akiva must be stated across three distinct cases of mixed newborn offspring.

Halachot from the daf

Corpse found equidistant between two cities regarding eglah arufah
Priest's share when twin male lambs emerge simultaneously
Entitlement to surviving twin male lamb if one dies
Priestly gifts obligation for the second animal of twin firstborns
Priestly gifts from an animal of uncertain firstborn status
Priestly gifts when a priest already took one doubtful firstborn
Priestly gifts from an animal of uncertain animal-tithe status
Surviving animal when two depositors leave animals with a neutral bailee
Surviving animal when a firstborn is deposited with a homeowner
Priest-shepherd whose firstborn mixes with a homeowner's animal in a courtyard
Offspring of two uncalved ewes: two males, male-female, or two males-female
Two uncalved ewes bearing two females and a male, or two of each
One uncalved ewe and one veteran ewe bearing two males or male-female

Gems from the Daf

Learn Bekhorot 18 sugya by sugya on Super Daf: the Gemara in Hebrew and English with Rashi, Tosafot, the Rishonim, the Rambam and the Shulchan Arukh woven in. Free.